Math Questions ratlu??

10th mein hu, RD ke kuch trigo ke examples wagera hain jinka pehla dusra step itna ajeeb sa hai ki mere mind mein kabhi possible hi nahi hai mai aisa step sochlu so I learned those few Qs for Preboards. But just thinking ki jee prep mein bhi aise hazaro Qs aayenge to ratt to sakta nahi and even Question banks mein. This shit is lingering in my mind for some time. Meri class ke kuch bachche hain aur jo aise examples ratt hi lete hain but never thought about this.